Automatic bagging machines



1969 E. J. CHAMBLESS, JR 3,421,286

AUTOMATIC BAGGING MACHINES Sheet Filed Aug. 5, 1966 &

1969 E. J. CHAMBLESS, JR

AUTOMATIC BAGGING MACHINES Sheet 2 of 3 Filed Aug.

1969 E. J. cHAMsLEss, JR 3,421,286

AUTOMAT I C BAGG ING MACHINES Filed Aug. 5, 1966 Sheet 3 of 5 UnitedStates Patent 3,421,286 AUTOMATIC BAGGING MACHINES Edward J. Chambless,Jr., Austin, Tex., assignor to St.

Regis Paper Company, New York, N.Y., a corporation of New York FiledAug. 5, 1966, Ser. No. 570,584

US. Cl. 53-190 Int. Cl. B65!) 5/00; B65b 9/00 Claims ABSTRACT OF THEDISCLOSURE This invention relates to automatic bagging machines and moreparticularly to machines of that class adapted for applying bags such asof polyethylene or other plastic film material to loaves of bread, othercomestibles or objects.

The invention involves certain improvements making it possible to usesuch machines for applying plastic film bags, which may vary somewhatfrom their intended dimensions or have other varying characteristics,and to do so while avoiding disruption of the bag and consequent failureof the machine to operate reliably and rapidly.

By way of example, the invention will be herein described andillustrated as applied to a so-called Mark 50 automatic bread packagingmachine, now well known on the market and as described and illustratedin the drawings of a manual published in March 1965 for that machine byCommodity Packaging Co., Inc. of Yakima, Wash. (now Bakery MachineryDivision, American Machine & Foundry Co., 2115 W. Laburnum Avenue,Richmond, Va. 23227). Features of the invention may be applied to othermachines of that class adapted for like or similar purposes.

In machines of that type, spaced-apart scoop elements are reciprocatablymounted to travel endwise past an object such as a loaf of bread andenter into an open mouth of a plastic film bag and become spread apartsomewhat to grip the bag internally, the scoop elements being thenretracted for drawing the bag into the desired position surrounding theloaf. Such plastic film bags, although intended to be manufactured topredetermined sizes, nevertheless are necessarily produced very rapidlyand inexpensively with the film being heat-sealed along one or usuallytwo longitudinal lines. Under these circumstances the circumference ofthe bag, although intended to be of a certain predetermined size, mayvary somewhat from bag to bag due to variations in the character andposition of the lines of heat-sealing or due to variations in thestretchability of the film material under varying conditions. As aresult the scoop elements which enter the bag mouth and shape same toreceive the loaf, may from bag to bag tend to exert different amounts ofpressure against the interior surfaces of the bag walls. Thus eventhough the operating supports for the two scoop elements may becarefully adjusted so that they will expand in the bag to accuratelypredetermined spacedapart positions for accommodating a predeterminedsize of bag, yet, because of the variations in the successive bags, thescoop elements may in some cases overstretch "ice the mouths of thebags, or in other cases fit in place too loosely, and cause disruptionof the film of the bag or allow it to slip out of proper control. Evenif this only occurs infrequently, it will be necessary to stop themachine for a considerable period to clean away disrupted bags andpossibly mangled bread loaves or other commodities and also this willinterrupt the regular normal automated flow through the plant of thecommodity being made and bagged.

In accordance with the present invention this problem has beensurprisingly well overcome by providing in the linkage which operatesone of the scoop elements, for example the upper scoop element, means inthe form of an air-operated cylinder and piston device for so applyingpressure to the linkage as to urge such upper scoop element with auniform pressure against the upper inner wall of the mouth of the bag.That is, the pressure which the scoop element is thus caused to exertwill be uniform, even though the upward movement of the scoop element incoming into engagement within the inner wall of the mouth of the bag,will be stopped at varying levels depending on inaccuracies in thedimensions or character of successive bags.

It may be noted that efforts have been made so to arrange the linkagefor operating the scoop element that the latter will be pressed upwardlyessentially by spring means, but such means has not proven satisfactory,possibly because such machines operate with great rapidity and any suchspring means may not only inherently vary its pressure because ofvarying its tension, but also because of vibrating and oscillatingefiects which are avoided with the air pressure operated cylinder andpiston means in accordance with the present invention.

Various further and more specific objects, features and advantages ofthe invention will appear from the description given below, taken inconnection with the accompanying drawings, illustrating by way ofexample a prefer-red form of the invention.

In the drawings:

FIG. 1 is a side elevational view of the machine of the particular typeabove referred to and embodying the improvements of the presentinvention;

FIG. 2 is an enlarged elevational view of the parts of such a machinewhich are more particularly concerned with the improvements of thepresent invention;

FIG. 3 is a diagram illustrating the air-operated cylinder, piston andassociated air pressure connections used in accordance with a preferredexample of the invention; and

FIG. 4 is a vertical sectional view of a typical airoperated cylinderand piston means adapted for use for the present invention.

Referring in further detail to FIG. 1, the essential parts of theabove-mentioned type of machine will first be referred to. Suitableconveyor means, although not shown in FIG. 1, may extend generallyhorizontally from the position of the viewer transversely across the topof the machine as shown in FIG. 1, to convey loaves of bread or otherobjects to a packaging station at the position indicated at 19.Equipment indicated generally at 11, of any suitable known type, may beprovided for holding a stack of the initially fiat plastic film bagswhich are brought into a position so that as by use of air jets, themouth portion of each successive bag is blown to an open condition readyto receive spaced-apart upper and lower scoop elements as at 12, 13which are reciprocated endwise past the loaf of bread, for example,located at It to enter into the open mouth of the plastic bag which hasbeen made ready to receive same by the equipment at 11. Meanwhile aso-called blockade arrangement indicated generally at 14 is operated tothrust a blocking element 15 into contact with the end of the loaf toretain same against endwise movement at the packaging station while thescoop elements 12 and 13 have entered into and engaged within the mouthof the plastic bag. Then the scoop elements are retracted to pull thebag over the loaf at station 10, while the loaf is prevented from movingby the blockade device until the plastic bag is drawn into positionfully to contain the loaf, and the scoop elements are retracted to theposition shown in FIG. 1.

The scoop elements are carried by a shuttle element indicated at 16which reciprocates along a shaft 16a to move the scoop elements to andfro in the process of their reaching for a plastic film bag and drawingsame over the loaf. The shuttle element 16, as better shown in FIG. 2,may be operated by a link 17 pivotally connected at its upper endthereto about an axis 18. The other end of this link is pivotallyconnected about an axis 19 to a lever 20, which in turn is pivotallymounted about an axis as at 21 at the base of the machine. The lever isswung back and forth as by link means 22 which is of adjustable length,this link being pivotally connected at 23 to the lever 20 and at itsother end at 24 to a member 25 which may incidentally be a cam memberrotated about an axis 26 for operating the above-mentioned blockadearrangement.

During the reciprocating movement of the scoop elements 12 and 13, thevertical spacing therebetween is alternately increased and decreased bylinkage means so that the scoop elements enter the bag month while theyare colser together, and will then expand apart or become more separatedto engage the interior surfaces within the mouth of the bag and continuesuch engagement until the bag is pulled over the leaf of bread,whereupon their vertical spacing may be reduced again. With machines ofthe type above referred to, thisis accomplished by a cam 27 rotatable onaxis 26 and engaging a cam follower 28 mounted on an upstanding lever 29which is pivotally mounted at 29a.

Lever 29 is pivotally connected at 30 to a link member generallyindicated at 31, the other end of which is pivotally connected at 32 toa bell crank 33 having its central pivot at 21 and having an arm 33apivotally connected at 34 to a link 35. A spring 32a normally pullsagainst link means 31 and thereby acts to maintain cam follower 28 incontact with cam 27. The link is pivotally connected at 35a to a bellcrank 36 pivotally mounted on an axis at 19. Another arm 36a of thisbell crank is pivotally connected at 37 to a link 38, the latter in turnbeing pivotally connected at 39 to another bell crank 40 having itscentral pivot at 18 and having another arm 40a which is slotted toprovide an adjustable pivotal connection 41 to a further link 42, thelatter in turn being pivotally connected at 43 to a rocker arm 44. Therocker arm 44 is pivotally mounted at 45 and carries at its lefthand end44a the upper scoop element 12.

It will be apparent that the linkage by which the upper scoop element istilted by rotation of cam 27, is such that the tilting movement can beimparted during reciprocation of the shuttle member 16 withoutinterfering with the reciprocating movements of the scoop elements.

The parts of the machine as thus far described, with the exception ofthe construction of the link means 31 as hereinafter explained, may allbe constructed and operated in accordance with the known machines of theabove-mentioned type. Of course, the various parts are power driven bysuitable mechanical connections as from a motor 46 (FIG. 1) so that eachportion of the machine will operate in proper synchronous relation tothe other portions and the accompanying conveying means.

Referring further to the link 31, in former examples of this machine,this link was simply adjustable in length 'by reason of its threadedends, and upon such adjustment and possible adjustment of various othersof the links, the scoop element 12 would be tilted up and down asrequired during each stroke and as above explained. Once the linkageswere thus adjusted, although the scoop 12 and its rocker arm support 44amight have some resiliency, yet the limits of the up and down movementsthereof would be substantially fixed and not variable without stoppingthe machine and readjusting the linkage or other parts. However, for theabove-explained reasons, the desirable upward swinging movement of thisscoop element may vary from bag to bag, so that it should stop at thelevel of one or another of the dotted lines, as indicated at 48 (seeupper left corner of FIG. 2), and in doing so, apply substantially apredetermined upward pressure against the inner surface of the mouths ofbags even if of inaccurately-formed dimensions. To make this possible inaccordance with the present invention, the link 31 has interposedtherein the above-mentioned cylinder and piston means, indicated at 49with the piston operated by air pressure in a direction tending to pullagainst the bell crank arm 35. By following through the linkage shown inFIG. 2, it will be apparent that this pulling effect acts to apply anupward tilting pressure to the scoop rocker arm 44a, but at no time agreater pressure than that corresponding to the air pressure in thedevice 49. Of course, while compressed air Will usually be used tooperate the device 49, other gases should be considered as equivalentfor the purpose.

One example of the device 49 suitable for use with the invention isfurther illustrated in the sectional view of FIG. 4, wherein thecylinder is indicated at 50, a piston at 51 and a piston rod at 52connected as shown in FIG. 2 to the pivot point 32 on the bell crank arm33.

The device 49 may, with a machine of the type abov referred to, have aninternal cylinder diameter for example in the neighborhood of inch andthe air pressure therein may be maintained in the range of 50 to 70pounds per square inch when the machine is operating to apply commontypes of plastic film bags to bread. However, the pressure may varyaccording to the strength and size of the bag being used. The piston mayhave a maximum stroke of about one inch.

As shown in FIG. 3, the left-hand end of the device 49 is coupled bysuitable means at 53 to the remainder of the link means 31 and the righthand end of the device 49 may have a suitable stufiing box or the like54 through which the rod 52, shown in FIG. 4, may slide and extend tothe pivotal connection 32. As further indicated in FIG. 3, the air underpressure may be brought into the right hand end of the device 49 througha connection 55 of a conduit running to a pressure regulator 56 andthence to a suitable filter 57 connected as by a quick-detachableconnection if desired at 58 and to a source of .air supply. A suitableair-operated electrical switch may be provided at 59 to open theelectrical circuit of the motor drive for the machine and to thusprevent the operation of the bagging machine when the supply airpressure drops below an acceptable minimum value such as, for example,40

pounds per square inch. The left hand end of device 49 (as shown in FIG.4) may have a vent 60 open to the atmosphere. The overall length of thelink means 31 may, of course, be adjusted as heretofore by suitablescrewthreaded connection means at 61. Ordinarily it should be adjustedto such length that the piston 51 will normally be near the left handend of the cylinder as shown in FIG. 4. And when the scoop member 12 inengaging the inside surface of the mouth of the bag, meets withresistance, it will apply a predetermined pressure depending upon thepressure in the cylinder 50, and thereupon stop the upward movement ofthe scoop without disrupting the bag and yet insuring adequate andpredetermined pressure against the bag surface.

Although a certain particular embodiment of the invention is hereindisclosed for purposes of explanation, further modifications thereof,after study of this specification, will be apparent to those skilled inthe art to which the invention pertains. Reference should accordingly behad to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. In a machine for automatically applying bags of sheet material toobjects to be bagged therein, the machine having spaced-apart scoop-likeelements, means for reciprocably mounting same to travel past the objectto be bagged and to enter into the open mouth of a bag, mechanicallinkage mechanism being provided to then spread apart said elementssomewhat further and into engagement with the interior surfaces of themouth of the bag, said reciprocable mounting means then acting toretract said elements with the bag thereon and to pull the same intosurrounding relationship to the object being bagged, the improvementwhich comprises providing in said mechanism an air pressure operatedmeans operable subsequent to engagement between said scoop-like elementsand the interior surfaces of the mouth of the bag for applying apredetermined force acting through said mechanism to cause said scoopmeans to exert a predetermined spreading pressure against the interiorsurfaces of the mouths of the bags notwithstanding variations of thelatter from normal size when spread open.

2. Machine in accordance with the foregoing claim 1 and in which saidreciprocable mounting means is also arranged to reciprocably carrytherewith a portion at least of said mechanism for further spreadingsaid elements.

3. A machine in accordance with the foregoing claim 1 and in which saidai-rpressure-operated means comprises a cylinder and piston device.

4. In a machine for automatically applying bags of sheet material toobjects to be bagged therein, the machine having spaced-apart scoop-likeelements, means for reciprocably mounting same to travel past the objectto be bagged and to enter into the open mouth of a bag, a camoperatedlinkage mechanism being provided to then spread apart said elementssomewhat further and into engagement with the interior surfaces of themouth of the bag, said reciprocable mounting means then acting toretract said elements with the bag thereon and to pull the same intosurrounding relationship to the object being bagged; the improvementwhich comprises providing in said mechanism an air pressure operatedcylinder and piston device for applying a predetermined force as apulling force acting through said mechanism to cause said scoop means toexert a predetermined spreading pressure against the interior surfacesof the mouths of the bags notwithstanding variations of the latter fromnormal size when spread open.

5. Apparatus in accordance with the foregoing claim 4 and in which saidmechanism for spreading the elements further apart in the mouth of thebag is operably associated with said reciprocable means to move saidelements closer together again after the object has been bagged.

6. In a machine for automatically applying bags of sheet material toobjects to be bagged therein, the machine having spaced-apart scoop-likeelements, means for reciprocably mounting same to travel past the objectto be bagged and to enter into the open mouth of a bag, mechanism beingprovided to then spread apart said elements somewhat further and intoengagement with the interior surfaces of the mouth of the bag, saidreciprocable mounting means then acting to retract said elements withthe bag thereon and to pull the same into surrounding relationship tothe object being bagged; the improvement which comprises providing insaid mechanism an air pressure operated means for applying apredetermined force acting through said mechanism to cause said scoopmeans to exert a predetermined spreading pressure against the interiorsurfaces of the mouths of the bags notwithstanding variations of thelatter from normal size when spread open, a pressure-operable electricalswitching means operably responsive to the air supply pressure to saidair pressure operated means, to stop a motor drive for the machine whensaid pressure drops to a predetermined value below which said airpressure operated means will not effectively produce a sufiicientspreading pressure on said elements to maintain the bag thereon duringthe bagging operation.

References Cited UNITED STATES PATENTS 2,850,855 9/1958 Offuit 53-272,973,610 3/1961 Randall 53-188 3,358,414 12/1967 Hersh et 'al 53261 XTHERON E. CONDON, Primary Examiner.

R. L. SPRUILL, Assistant Examiner.

US. Cl. X.R.

